Why are Crohn's comorbidities important?

"Comorbidity in inflammatory bowel disease" in World J Gastroenterol (2011)

Why is comorbidity important?
Firstly, it is obvious that comorbid conditions cannot be overlooked in a patient with IBD. The existence of comorbidity can significantly change several scenarios of medical practice[2]. (1) Clinical manifestations of IBD and its activity can be altered or confused by associated diseases; (2) Prognosis of IBD will also be influenced; (3) Whenever a patient with significant comorbidity is seen by us, we step outside the realms of medical evidence. As a rule, randomized controlled trials exclude patients with comorbidity, and so their conclusions are not necessarily applicable to such situations; (4) The use of drugs for the treatment of IBD is limited by the increased importance their pharmacologic or collateral effects can have on a person with comorbid conditions; and (5) Frequently, it is more important than ever to set up multidisciplinary teams to empower patient care, or, at least, to assure that channels of collaboration and mutual consultation are as fluid and reliable as possible.
"The comorbid occurrence of other diagnoses in patients with ulcerative colitis and Crohn's disease" in American Journal of Gastroenterology (2001)
"Ulcerative colitis and Crohn's disease showed, in general, similar patterns of comorbidity. Both diseases were associated with similar sets of GI complications, such as intestinal obstruction and stasis, mucosal inflammation and infection, vascular complications, and complications related to fistula and abscess formation. Extraintestinal complications of both IBD involved disorders of the hepatobiliary system, urinary system, and various coagulopathies. Ulcerative colitis alone was found to be associated with Hirschsprung's disease and schizophrenia, whereas Crohn's disease alone was found to be related with osteoporosis and amyloidosis. CONCLUSIONS: No completely unexplained or hitherto undescribed association was revealed. The numerous intestinal and extraintestinal complications associated with IBD serve as a reminder of the systemic nature and the resultant clinical severity of both ulcerative colitis and Crohn's disease."

"Increased Risks of Developing Anxiety and Depression in Young Patients With Crohn's Disease" in Inflammatory Bowel Disease (2011)

"Compared with matched CD-free controls, young patients with CD had significantly greater risks of developing anxiety disorders and depression, were more likely to receive psychotropic treatments, and had significantly greater risks of developing persistent anxiety and depression."

"Increased risk for coronary heart disease, asthma, and connective tissue diseases in inflammatory bowel disease" in Journal of Crohn's and Colitis (2011)
"In addition to many immune-mediated diseases, CHD appeared to be more common in IBD than in control patients, especially in females. The reason is unknown, but chronic inflammation may predispose to atherosclerosis. This finding should encourage more efficacious management of underlying cardiovascular risk factors, and probably also inflammatory activity in IBD."